Long-Term Debt To Affiliated Trusts (Schedule Of Distribution Rates Paid) (Details)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.79%	3.61%	2.36%
Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.79%	2.36%	1.81%
Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.61%	3.61%	2.36%